PATTERN RECOGNITION FOR AUTOMATED WIRE BONDING.

Abstract

The design and development of an integrated pattern-recognition system for transistor/LED wire bonding is presented. The system uses a M6809 microprocessor for computation. Three recognition algorithms are studied, and their relative performances are compared. The firts algorithm based on edge extraction and projection is relatively slow but is a candidate for hardware implementation at higher speeds. The second algorithm based on the Freeman tracer is the fastest, but not intelligent enough to identify connected regions. A new algorithm called the 'connected-tracer' algorithm is proposed, which solves the problem of simple connectiveness with a speed performance of around 0. 1 s using a 1 MHz processor. A variety of die samples of different sizes, scribing and attachment methods are tested. The results indicate that the system developed is both reliable and effective for fully automated transistor/LED wire bonding.